/* Linha do tempo dos sistemas operacionais
   Paleta: papel cinza-esverdeado + rampa de matiz que avança com o tempo. */

:root {
  --paper:        #e4e7e1;
  --paper-sunk:   #dcdfd8;
  --ink:          #191d1a;
  --ink-soft:     #4e5651;
  --rule:         #c4c9c0;
  --rule-faint:   #d2d6cd;

  --era-1: #5e6c73;   /* 1956  aço */
  --era-2: #4c7391;
  --era-3: #2c5e9e;
  --era-4: #2144ae;
  --era-5: #3a2fb0;
  --era-6: #5b2ba8;   /* 2026  violeta */

  --sans: "IBM Plex Sans", ui-sans-serif, system-ui, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, "SF Mono", Menlo, Consolas, monospace;

  --gutter: clamp(1.25rem, 5vw, 4.5rem);
  --year-col: 6.25rem;
  --rail-gap: 1.75rem;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper:      #14181a;
    --paper-sunk: #1b2023;
    --ink:        #e2e6e0;
    --ink-soft:   #9aa39d;
    --rule:       #333b3d;
    --rule-faint: #262d30;

    --era-1: #9aa8af;
    --era-2: #74a0bd;
    --era-3: #5e94dd;
    --era-4: #7290f2;
    --era-5: #8f82f6;
    --era-6: #ab80ef;
  }
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  padding: 0 var(--gutter) 0;
  background: var(--paper);
  color: var(--ink);
  font: 400 17px/1.62 var(--sans);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3 { margin: 0; font-weight: 600; letter-spacing: -0.02em; }
p { margin: 0; }
i { font-style: italic; }

/* ---------- cabeçalho ---------- */

.masthead {
  max-width: 68rem;
  margin: 0 auto;
  padding-block: clamp(3.5rem, 11vh, 7rem) clamp(2.5rem, 6vh, 4rem);
}

.masthead h1 {
  font-size: clamp(2.3rem, 6.2vw, 4.15rem);
  line-height: 1.03;
  letter-spacing: -0.035em;
}

.standfirst {
  margin-top: 1.6rem;
  max-width: 46ch;
  font-size: 1.06rem;
  line-height: 1.58;
  color: var(--ink-soft);
}

/* ---------- diagrama de linhagens ---------- */

.lineage {
  max-width: 68rem;
  margin: 0 auto;
  padding-block: clamp(2rem, 5vh, 3rem) clamp(2rem, 5vh, 3.25rem);
  border-top: 1px solid var(--rule);
}

.lineage h2 {
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: 0;
}

.lineage-intro {
  margin-top: 0.35rem;
  max-width: 44ch;
  font-size: 0.95rem;
  color: var(--ink-soft);
}

.chart-scroll { margin-top: 2.25rem; }

.chart {
  position: relative;
  padding-top: 2rem;
}

.chart-hint { display: none; }

.chart-grid {
  position: absolute;
  inset: 2rem 0 1.9rem var(--lane-col, 8.25rem);
  pointer-events: none;
}

.chart-grid span {
  position: absolute;
  top: 0;
  bottom: 0;
  width: 1px;
  background: var(--rule-faint);
}

.lane {
  position: relative;
  display: grid;
  grid-template-columns: var(--lane-col, 8.25rem) 1fr;
  align-items: center;
  height: 2.15rem;
}

.lane-name {
  padding-right: 0.9rem;
  text-align: right;
  font-size: 0.78rem;
  line-height: 1.2;
  color: var(--ink-soft);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.lane-track { position: relative; height: 100%; }

.lane-bar {
  position: absolute;
  top: 50%;
  height: 5px;
  margin-top: -2.5px;
  border-radius: 2.5px;
  opacity: 0.5;
  transform-origin: left center;
}

.mark {
  position: absolute;
  top: 50%;
  width: 13px;
  height: 13px;
  margin: -6.5px 0 0 -6.5px;
  padding: 0;
  border: 2.5px solid var(--paper);
  border-radius: 3px;
  background: currentColor;
  color: inherit;
  cursor: pointer;
  transition: transform 140ms ease, box-shadow 140ms ease;
}

.mark:hover,
.mark:focus-visible { transform: scale(1.35); }

.mark:focus-visible {
  outline: 2px solid var(--ink);
  outline-offset: 3px;
}

.chart-axis {
  position: relative;
  height: 1.9rem;
  margin-left: var(--lane-col, 8.25rem);
  padding-top: 0.55rem;
  border-top: 1px solid var(--rule);
}

.chart-axis span {
  position: absolute;
  top: 0.5rem;
  font: 400 0.72rem/1 var(--mono);
  color: var(--ink-soft);
  transform: translateX(-50%);
}

.chart-axis span:first-child { transform: none; }
.chart-axis span:last-child  { transform: translateX(-100%); }

.tip {
  position: absolute;
  z-index: 5;
  transform: translate(-50%, -100%);
  margin-top: -13px;
  padding: 0.3rem 0.55rem;
  border-radius: 4px;
  background: var(--ink);
  color: var(--paper);
  font-size: 0.78rem;
  line-height: 1.25;
  white-space: nowrap;
  pointer-events: none;
  opacity: 0;
  transition: opacity 120ms ease;
}

.tip[data-show="1"] { opacity: 1; }
.tip b { font: 500 0.78rem/1.25 var(--mono); font-weight: 500; margin-right: 0.45em; }

/* ---------- linha do tempo ---------- */

.timeline {
  max-width: 68rem;
  margin: 0 auto;
}

.era { padding-block: clamp(2.5rem, 6vh, 4rem) 0; }

.era-head {
  display: grid;
  grid-template-columns: var(--year-col) 1fr;
  align-items: start;
  padding-bottom: 1.5rem;
}

.era-span {
  grid-column: 1;
  grid-row: 1;
  text-align: right;
  padding-right: var(--rail-gap);
  padding-top: 0.5rem;
  font: 400 0.8rem/1.5 var(--mono);
  color: var(--ink-soft);
}

.era-head h2 {
  grid-column: 2;
  grid-row: 1;
  padding-left: var(--rail-gap);
  max-width: 26ch;
  font-size: clamp(1.28rem, 2.4vw, 1.7rem);
  line-height: 1.15;
  color: var(--era);
}

.entries {
  position: relative;
  color: var(--era);
}

.entries::before {
  content: "";
  position: absolute;
  left: var(--year-col);
  top: 0.2rem;
  bottom: 0;
  width: 1px;
  background: currentColor;
  opacity: 0.18;
}

/* segmento aceso: com JS, aparece quando o marco é alcançado */
.entry::before {
  content: "";
  position: absolute;
  left: var(--year-col);
  top: 0;
  bottom: 0;
  width: 1px;
  background: currentColor;
  opacity: 0.55;
  transition: opacity 600ms ease;
}

.entry {
  position: relative;
  display: grid;
  grid-template-columns: var(--year-col) 1fr;
  padding-bottom: 2.4rem;
}

.entry::after {
  content: "";
  position: absolute;
  left: calc(var(--year-col) - 3px);
  top: 0.52rem;
  width: 7px;
  height: 7px;
  border-radius: 2px;
  background: currentColor;
}

.entry-year {
  text-align: right;
  padding-right: var(--rail-gap);
  font: 500 1.02rem/1.55 var(--mono);
  color: var(--era);
}

.entry-body {
  padding-left: var(--rail-gap);
  max-width: 40rem;
}

.entry-body h3 {
  font-size: 1.2rem;
  line-height: 1.3;
  color: var(--ink);
}

.entry-body p {
  margin-top: 0.55rem;
  max-width: 62ch;
  color: var(--ink-soft);
}

.entry-last .entry-body h3 { font-size: 1.35rem; }
.entry-last .entry-body p { color: var(--ink); }

/* ---------- leitura conforme o scroll ---------- */

.js .entry::before,
.js .entry::after,
.js .entry-year,
.js .entry-body { opacity: 0.25; }

.js .entry-year,
.js .entry-body { transition: opacity 560ms ease; }
.js .entry::after { transition: opacity 560ms ease; }

.js .entry.is-read::before { opacity: 0.55; }
.js .entry.is-read::after,
.js .entry.is-read .entry-year,
.js .entry.is-read .entry-body { opacity: 1; }

/* cursor fixo: percorre 1956-2026 na mesma escala do diagrama */
.scrubber {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 20;
  opacity: 0;
  pointer-events: none;
  transition: opacity 320ms ease;
}

.scrubber[data-on="1"] { opacity: 1; }

.scrubber-track {
  height: 2px;
  background: var(--rule-faint);
}

.scrubber-fill {
  height: 100%;
  width: 0;
  background: var(--era, var(--era-1));
  transition: background-color 500ms ease;
}

.scrubber-year {
  position: absolute;
  top: 0.55rem;
  left: 0;
  transform: translateX(-50%);
  padding: 0.1rem 0.4rem;
  border-radius: 3px;
  background: var(--paper);
  font: 500 0.78rem/1.4 var(--mono);
  color: var(--era, var(--era-1));
  transition: color 500ms ease;
}

/* destaque temporário ao chegar pelo diagrama */
.entry.is-target .entry-body {
  animation: settle 1.6s ease-out;
}

@keyframes settle {
  0%, 55% { background: color-mix(in srgb, var(--era) 13%, transparent); }
  100%    { background: transparent; }
}

/* ---------- mensagens de carregamento e falha ---------- */

.loading,
.aviso {
  max-width: 68rem;
  margin: clamp(2rem, 5vh, 3rem) auto;
  padding: 1rem 1.15rem;
  border-left: 2px solid var(--era-4);
  background: var(--paper-sunk);
  font-size: 0.95rem;
  line-height: 1.65;
  color: var(--ink-soft);
}

code {
  padding: 0.1em 0.3em;
  border-radius: 3px;
  background: var(--paper-sunk);
  font: 400 0.88em/1 var(--mono);
}

.aviso code { background: var(--paper); }

/* ---------- rodapé ---------- */

.colophon {
  max-width: 68rem;
  margin: 0 auto;
  padding-block: clamp(3rem, 8vh, 5rem);
  border-top: 1px solid var(--rule);
  margin-top: clamp(2.5rem, 6vh, 4rem);
  font-size: 0.92rem;
  color: var(--ink-soft);
}

.colophon-meta { margin-top: 0.35rem; }

/* ---------- animação de entrada (uma única vez) ---------- */

@media (prefers-reduced-motion: no-preference) {
  .chart[data-animate="1"] .lane-bar { animation: draw 620ms cubic-bezier(.2,.7,.3,1) backwards; }
  .chart[data-animate="1"] .mark     { animation: pop 260ms ease-out backwards; }
}

@keyframes draw { from { transform: scaleX(0); } }
@keyframes pop  { from { opacity: 0; transform: scale(0.4); } }

@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
  html { scroll-behavior: auto !important; }

  /* sem a revelação progressiva: todo o conteúdo já legível */
  .js .entry::after,
  .js .entry-year,
  .js .entry-body { opacity: 1; }
  .js .entry::before { opacity: 0.55; }
}

/* ---------- telas estreitas ---------- */

/* o diagrama precisa de escala mínima: abaixo dela, rola na horizontal */
@media (max-width: 760px) {
  .chart-scroll {
    overflow-x: auto;
    overscroll-behavior-x: contain;
    scrollbar-width: thin;
    padding-bottom: 0.5rem;
  }

  .chart { min-width: 42rem; }
  .chart-hint { display: inline; }
}

@media (max-width: 680px) {
  :root { --year-col: 3.75rem; --rail-gap: 1.1rem; }

  body { font-size: 16px; }
  .lane-name { font-size: 0.72rem; padding-right: 0.7rem; }
  .lane { height: 1.95rem; }
  .entry-year { font-size: 0.92rem; }
  .entry-body h3 { font-size: 1.12rem; }

  /* cabeçalho de época empilhado, para o intervalo não espremer na coluna */
  .era-head { display: block; padding-bottom: 1.25rem; }
  .era-span { text-align: left; padding: 0 0 0.3rem; }
  .era-head h2 { padding-left: 0; max-width: none; }
}

/* ---------- impressão ---------- */

@media print {
  body { background: #fff; color: #000; font-size: 11pt; padding: 0; }
  .lineage, .mark, .tip { display: none; }
  .entry { page-break-inside: avoid; }
  .era { page-break-before: auto; }
  .entry-body p, .standfirst, .entry-year { color: #000; }
}